Boride catalyst for epoxidizing olefinic compounds

ABSTRACT

A novel catalyst material of a boron containing substance for catalyzing the liquid phase oxidation of an olefin with an organic hydroperoxide to the corresponding oxirane is disclosed. The novel catalyst materials are characterized as binary or ternary boride compounds having the general formula M x  B y  or M x  B y  R z  wherein x is an integer from 1-5; y is an integer from 1-2; z is an integer from 1-4; B is boron; M is an element selected from the groups II-A, III-B, IV-B, V-B, VI-B, VII-B, VIII, III-A, IV-A, and V-A of the Periodic Table, the rare earths, and the actinides; and R is an element different from M selected from the same group of elements in the Periodic Table as M. The preferred catalyst materials are those boron containing substances which are substantially insoluble in the reaction mixture containing the organic hydroperoxides, olefins and products. 
     Also disclosed is a method for liquid phase epoxidation of an olefinic compound with an organic hydroperoxide at lower temperatures, e.g. 25° C. to 200° C. and a pressure sufficient to maintain the mixture substantially in liquid phase in the presence of a catalytically effective amount of the novel catalyst material.

This is a division of application Ser. No. 565,004, filed Apr. 4, 1975now U.S. Pat. No. 4,038,290.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to catalyst material for expediting theoxidation of an olefin to the corresponding oxirane; and, moreparticularly to a catalyst material of a boron containing substance forcatalyzing the liquid phase epoxidation of olefins with organichydroperoxides.

2. Prior Art

Oxiranes or epoxides, while being valuable commercial products in and ofthemselves, are also commercially valuable as starting reactants forsynthesizing many useful compounds such as polyether polyols forurethane systems. Over the years many methods have been disclosed forsynthesizing such compounds. The majority of these methods involve theoxidation of the corresponding olefin. For example, it is known thatethylene can be converted to the corresponding epoxide by a vapor phasepartial oxidation with molecular oxygen over a silver catalyst. However,the ease of olefin oxidation varies greatly depending upon the size andstructure of the olefinic starting reactant and therefore many of thedisclosed processes are not effective for epoxiding olefins in general.

Recently it has been disclosed that olefinically unsaturated organiccompounds can be oxidized to the corresponding oxirane compound inliquid phase with organic hydroperoxides in the presence of variouscatalyst. For example, U.S. Pat. No. 3,350,422 issued Oct. 31, 1967 toKollar discloses that soluble vanadium compounds can be employed as ahomogeneous catalyst for oxidation of olefins with organichydroperoxide. Specifically, hydrocarbon soluble organometalliccompounds of vanadium are disclosed as being effective as expoxidationcatalysts. However, the insoluble vanadium catalysts, such as forexample, vanadium pentoxide are disclosed as substantially ineffectivein catalyzing the epoxidation of propylene. More recently, U.S. Pat. No.3,634,464 issued Jan. 11, 1972 to Wulff, et al. describes the use ofoxides of molybdenum on a solid inorganic oxide support modified byinclusion therewith of bismuth or certain rare earth metal oxides as acatalyst for the epoxidation of olefins with an organic hydroperoxide.The catalyst is substantially insoluble in the epoxidation reactantmixture, providing a heterogeneous system. The presence of a minorproportion of bismuth or certain rare earth oxides as catalyst modifiersis disclosed as a critical feature of the catalytic action.

Additionally, it has been disclosed that silicides or siliceous solidshaving high surface to mass ratio are particularly effective ascatalytic substances in the epoxidation of olefins with organichydroperoxides. Specifically, U.S. Pat. No. 3,702,855 issued Nov. 14,1972 to Bell et al. discloses a catalytic material selected from metalsilicides of titanium, zirconium, vanadium, mobium, chromium,molybdenum, and tungsten is effective as a liquid phase epoxidationcatalysts.

More recently it has been disclosed in U.S. Pat. No. 3,832,368 issuedAug. 27, 1974 to Fetterly et al. that the epoxidation of ethyleniccompounds to the corresponding oxirane compound is catalyzed by thepresence of a born oxide, a dehydrated boric acid, and the hydrocarbylesters thereof. The compounds disclosed in this patent which are usefulas catalysts contain at least one B-O-B linkage.

The previously described catalysts suffer from one or more disadvantageswhen employed as liquid phase epoxidation catalysts. For example, manyof the previously known catalyst materials are expensive and difficultto prepare, and/or are highly selective to oxidation of specificolefinic compounds, and/or are difficult to use requiring specialapparatus or highly selective reaction conditions, and/or are limited toheterogeneous or homogeneous type reaction systems.

Unexpectedly it has been found that a large class of boron containingsubstances are effective in catalyzing liquid phase epoxidation of anolefin with an organic hydroperoxide to the corresponding oxirane. Thesesubstances may be generally categorized as binary and ternary boridecompounds consisting of boron and at least one element selected fromgroups II-A, III-B, IV-B, V-B, VI-B, VII-B, VIII, III-A, IV-A and V-A ofthe Periodic Table, the rare earths and the actinides. Because of thewide range of boron containing substances effective in catalyzing liquidphase epoxidation of an olefin with an organic hydroperoxide, thecatalyst may be selected to form a substantially heterogeneous systemwith the reactants or a substantially homogeneous system with thereactants. Further, boron containing substances of the instant inventionare easily obtainable, relatively inexpensive and easy to handle.Because of the wide range of boron substances which are showncatalytically active, a particular compound can be matched to aparticular epoxidation reaction thus achieving somewhat superiorselectivity and yield. Mixtures of these boron substances can also beused to afford specific selectively.

SUMMARY OF THE INVENTION

According to the invention, a catalyst material of a boron containingsubstance useful for the epoxidation of an olefinic unsaturated compoundwith an organic hydroperoxide consists essentially of substancescontaining boron and at least one element selected from groups II-A,III-B, IV-B, V-B, VI-B, VII-B, VIII, III-A, IV-A, and V-A of thePeriodic Table, the rare earths, and the actinides. Specifically thecatalyst material of the instant invention may be characterized as thebinary borides and the ternary borides having the general formularespectively M_(x) B_(y) and M_(x) B_(y) R_(z) wherein x is an integerfrom 1 to 5; y is an integer from 1 to 12; z is an integer from 1 to 4;B is boron; M is a single element selected from the above grouping and Ris an element selected from the above grouping but different from M.

According to a preferred embodiment, the catalyst material is a boroncontaining substance generally characterized as a binary boride which isnot dissolved or attacked by the reaction mixture containing the organichydroperoxide, olefins, and by-products.

According to another aspect of the invention, the epoxidation of anolefinically unsaturated compound to a corresponding oxirane derivativeemploying organic hydroperoxide as an epoxidizing agent is carried outin the presence of a catalytic amount of the boron containing substanceat lower temperatures under liquid phase conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The catalyst materials in accordance with a preferred embodiment arethose boron containing substances which are not substantially dissolvedor attacked by the reactants or product mixtures under the reactionconditions encountered in the epoxidation of olefinic compound to thecorresponding oxirane with organic hydroperoxides. These catalystmaterials may be generally employed in the liquid phase heterogeneousepoxidation systems wherein organic compounds having at least onealiphatic olefinically unsaturated carbon-carbon bond and from 2 to 60carbon atoms are oxidized with an organic hydroperoxide. Further, apreferred epoxidation is carried out in the presence of certain boridesas hereinafter particularly described in the presence of reactants andunder conditions as further set forth herein.

CATALYST MATERIALS

The catalysts used within the scope of the instant invention aregenerally boron containing substances effective in catalyzing the liquidphase epoxidation of an olefin with an organic hydroperoxide. Thesesubstances are characterized as boride compounds of boron and at leastone element selected from group II-A, III-B, IV-B, V-B, VI-B, VII-B,VIII, III-A, IV-A and V-A of the Periodic Table, the rare earth and theactinides. More particularly these boride compounds may be either theso-called binary borides or the ternary borides. The binary borides maybe represented by the general formula M_(x) B_(y) wherein B is boron; Mis an element selected as above; x is an integer from 1 to 5; B is boronand y is an integer from 1 to 12. The ternary borides may be representedby the general formula M_(x) B_(y) R_(z) wherein M, x, B and y representelements or integers as described herein above, R is an element selectedfrom the same periodic groups as M but is an element different from M inany given compound and z is an integer from 1 to 5.

The preferred catalytic materials are the binary borides. The preferredbinary boride compounds are those catalysts which are not dissolved orattacked by the reaction mixtures containing the organic hydroperoxides,olefins, and products. The preferred catalytic materials thus formsubstantially heterogenous systems with the liquid reactants andproducts. Preferred catalysts are LaB₆, CeB₆, ZrB₂, NbB, WB, W₂ B₅,MnB,NiB, AlB₂, and AlB₁₂. Other examples of boride compounds useful asinsoluble catalysts are CaB₆, TiB₂, ZrB₁₂, HfB₂, TaB₂, FeB, Co₃ B, Co₂B, CoB, SiB₄, SiB₆, and B₄ C.

It should be noted that the empirical formulas given herein do notnecessarily represent the exact stoichiometry of the catalytic materialbut rather represent particular crystalline phases which may benonstoichiometric due to lattice defects, vacant sites and the like. Itis intended that the scope of the instant invention cover all of theso-called binary and ternary borides represented by the formulas set outherein above, which include but are not limited to borides havingisolated boron atoms such as for example M₄ B, M₃ B, M₂ B, M₅ B₂ and M₇B₃ ; borides having single and double chains of boron atoms, i.e. thosecrystalline structures where a boron, boron linkage exist such as M₃ B₂and M₄ B₃ and M₃ B₄ ; borides having two dimensional nets such as thoserepresented by the formula MB₂ and M₂ B₅ ; and borides having a threedimensional boron network such as those having the formulas MB₄, MB₆,and MB₁₂.

As used herein, solubility and insolubility are relative terms. That is,those boron containing compounds which are characterized as formingheterogeneous systems may be in fact somewhat soluble in the reactionmixtures. Likewise, so-called soluble boron containing substances maynot form a completely homogeneous single phase with the reactants andreaction products. When utilizing the so-called soluble boron containingsubstances, it is preferable that sufficient catalyst be used to createa heterogeneous system.

The exact physical form of the catalyst is not important. It may be usedas a powder, lumps, pellets, spheres, and the like; as adherent films onmetals or other supports; and as coatings on supports such as alumina,silica or clay. Additionally, the catalyst of the instant invention maybe extruded or compressed to various shapes as to form a combinationwith adhering materials such as binders, fillers, extenders, and thelike.

Additionally, it will be realized by those skilled in the art thatmixtures of one or more of the boride catalytic material may be used toprovide, for example, selectivity in epoxidizing certain olefiniccompounds.

OLEFINICALLY UNSATURATED REACTANTS

The olefinically unsaturated materials which can be epoxidized inaccordance with the invention are generally organic compounds having atleast one aliphatic olefinically unsaturated carbon-carbon double bondcontaining from 2 to about 60 carbon atoms. In fact there are no knownolefinically unsaturated organic compounds which cannot be utilizedwithin the scope of the instant invention. For example, the olefinicreactant may be of acylic, monocyclic, bicyclic, or polycyclic olefinand may be a monoolefin, or a polyolefin. Additionally, the olefiniclinkages of the polyolefins may be conjugated or nonconjugated. Further,the olefinic reactant may be a hydrocarbon or a substituted hydrocarbonwith functional groups containing, for example, oxygen, halogen,nitrogen, or sulfur. Typical substititued functional groups are hydroxygroups; ether groups; ester groups; halogens such as chlorine andflorine; nitrile groups; amide groups; sulfur containing groups; nitrategroups; and the like. Examples of suitable olefinic reactants includeethylene, propylene, isobutylene, hexene-2, octene-1, eicosene-1,pipyrlene, vinylcyclohexene, dicyclopentadiene, styrene, allyl chloride,allyl alcohol, allyl acetate, allyl ether, allyl cyanide,cyclohexenecarbonitrile, soy bean oil, cotton seed oil and the like.

ORGANIC HYDROPEROXIDES

The organic hydroperoxides which can be used within the scope of theinstant invention are broadly any organic compound having at least onehydroperoxide moiety but free of functional groups which are deleteriousto the epoxidation reaction or are normally reactive with thehydroperoxides. A group of useful hydroperoxides is represented by theformula R'-OOH wherein R' is a hydrocarbyl or a substituted hydrocarbylgroup containing from 3 to 20 carbon atoms. The hydrocarbyl group may bealkylaryl, alkyl or substituted alkyl or arylalkyl. The substitutedalkyl or arylalkyl hydrocarbyl can contain oxygen incorporated into thefunctional group such as hydroxy, hydrocarbyloxy,hydrocarbyloxycarbonyl, hydrocarboyloxy, and the like. Additionally, thehydrocarbyl or substituted hydrocarbyl can contain halogens, e.g.,chlorine, florine, bromine and iodine.

The most preferred hydroperoxides are secondary and tertiaryhydroperoxides containing up to about 15 carbon atoms such as tertiarybutyl hydroperoxide, tertiary amyl hydroperoxide, cyclohexenehydroperoxide, tetralin hydroperoxide, cumene hydroperoxide, diisopropylbenzenehydroperoxide, α-methyl benzylhydroperoxide, and the like.

REACTION CONDITIONS

The epoxidation process of the instant invention is conducted in theliquid phase at lower temperatures, e.g. 25° C. to 200° C. and pressuressufficient to maintain the reactants and products substantially insolution. The mode of conducting the process of this invention is notcritical and may be accomplished by conventional methods such as batch,continuous or semi-continuous reactions. The temperature range at whichthe epoxidation reaction is carried out will depend upon the reactantand the catalyst employed but generally temperatures in the range fromabout 25° C. to 200° C. and preferably temperatures of about 50° C. toabout 150° C. are found sufficient. The reaction pressure are generallythose which are required to maintain the reactants, products, and thelike substantially in liquid phase. Pressures which range fromautogenous to about 200 atmospheres are generally sufficient forcarrying out the instant process.

The amount of reactants present in the reaction mixtures will generallydepend upon the olefin to be epoxidized and the hydroperoxide; but,generally molar ratios of olefin to hydroperoxide of from about 1:10 to100:1 and preferably from 1:2 to 10:1 have been found sufficient.Additionally, the molar ratios of hydroperoxide to the catalyst materialwill likewise depend upon the boron containing substance used, theolefin, the hydroperoxide and the reaction condition. Generally molarratios of hydroperoxide to catalyst from about 1:1 to 10,000:1 have beenfound sufficient, and preferably molar ratios of 1:1 to 1,000:1 areutilized.

Although it is not necessary, diluents and/or solvents which are liquidat reaction temperatures and pressures and are substantiallynondeleterious under reaction conditions to the reactant and productsmay be utilized. Useful solvents and diluents include aliphatic oraromatic hydrocarbons, alcohols, ethers, and esters. Aliphatic andaromatic halogenated hydrocarbons may also be utilized. Examples ofsuitable solvents include tertiary butyl alcohol, octane, cyclohexane,benzene, toluene, ethyl benzene, dichloromethane, ethylene dichloride,propylene dichloride, chlorobenzene, and the like.

Additionally, additives such as antioxidants and inorganic bases may beadded to the reaction mixture if desired. Examples of such additives aredi-t-butyl-p-cresol, p-methoxyphenol, diphenylamine, sodium oxide,magnesium oxide, and the like. Additives of these types are particularlyuseful for preventing undesirable side reactions.

The epoxidation reaction is suitably conducted by any of a variety ofprocedures. In accordance with one procedure the olefinic reactant andthe catalyst are initially charged into a suitable vessel equipped forreflux at autogenous pressure. The vessel is heated to reactiontemperatures and hydroperoxide is then added incremently with constantstirring. In another method, the reaction is effected in a continuousmanner such as by contacting the olefin reactant and the organichydroperoxide, in the presence of a solid catalyst which may besupported on a medium. In accordance with another method, the catalystand the hydroperoxide in a suitable solvent may be charged into anautoclave which is sealed and flushed with nitrogen. The olefiniccompound is then pressured into the sealed autoclave and the reactionmixture heated to reaction temperatures and stirred while reactionpressures are maintained. This method is particularly suited to gaseousolefinic compounds such as ethylene and propylene.

At the conclusion of the reaction, the product mixture can be separatedand the product recovered by conventional methods such as fractionaldistillation, selective extraction, filtration, and the like. Further,the catalyst, unreacted reactants, solvents and diluents if such areused can be recycled.

To further illustrate the process and the catalyst of the instantinvention the following examples are provided not as limitation but byfurther way of demonstrating the details of the invention.

EXAMPLE 1

In this example, the liquid phase epoxidation of an olefinic compoundwith an organic hydroperoxide was carried out in the presence of acatalytic amount of a boron containing substance in accordance with theinstant invention. A 250 ml. flask equipped with a stirrer, thermometer,reflux condenser and dropping funnel was charged with 84 g. octene-1 and1 g. tungsten boride (WB). The charged mixture was heated to 90° C. and90% tertiary butyl hydroperoxide was added dropwise until a total of 25g. had been added. The reaction mixture was then heated at reflux(108°-110° C.) for 220 minutes with stirring. The heated mixture wasallowed to cool and then the crude reaction product was analyzed. Theanalysis indicated a 36% yield of octene oxide based on the amount ofcharged hydroperoxide. The crude reaction product was filtered byconventional methods and the resulting filtrate was analyzed for metalcontent by atomic absorption analysis. No metals were detected in thefiltrate.

EXAMPLE 2-30

In these examples, various boron containing substances were used tocatalyze the liquid phase epoxidation of octene-1 with tertiary butylhydroperoxide by the procedure of Example 1. The results are shown inTable I.

                                      TABLE I                                     __________________________________________________________________________                                 Selectivity                                                                         Selectivity                                                             (based on                                                                           (based on                                                Moles    Conversion                                                                          hydro-                                                                              converted                                       Catalyst                                                                           Moles                                                                             hydro-                                                                             Time,                                                                             hydro-                                                                              peroxide)                                                                           octene)                                    Example                                                                            (wt. g)                                                                            octene                                                                            peroxide                                                                           Hours                                                                             peroxide                                                                            to epoxide                                                                          S.sub.2                                    __________________________________________________________________________    2    LaB.sub.6 (1)                                                                      0.375                                                                             0.125                                                                              6.0 82%   20%   88%                                        3    CeB.sub.6 (1)                                                                      0.375                                                                             0.125                                                                              5.0 90%   87%   94%                                        4    TiB.sub.2 (1)                                                                      0.75                                                                              0.25 7.0 16%   18%   40%                                        5    ZrB.sub.2 (3)                                                                      0.75                                                                              0.125                                                                              6.0 89%   87%   92%                                        6    NbB(3)                                                                             0.75                                                                              0.125                                                                              7.0 89%   91%   91%                                        7    TaB(1)                                                                             0.375                                                                             0.125                                                                              6.0 73%   15%   90%                                        8    TaB.sub.2 (1)                                                                      0.375                                                                             0.125                                                                              6.0 62%   16%   78%                                        9    WB(2)                                                                              0.75                                                                              0.125                                                                              7.0 86%   92%   92%                                        10   MnB(3)                                                                             0.75                                                                              0.125                                                                              6.0 52%   27%   84%                                        11   Co.sub.3 B-                                                                   Co .sub.2 B(1)                                                                     0.375                                                                             0.125                                                                              3.0 96%   15%   88%                                        12   CoB(1)                                                                             0.375                                                                             0.125                                                                              5.0 92%   29%   90%                                        13   NiB(1)                                                                             0.375                                                                             0.125                                                                              6.0 68%   81%   93%                                        14   FeB(2)                                                                             0.375                                                                             0.125                                                                              6.0 45%   22%   86%                                        15   AlB.sub.2 (3)                                                                      0.75                                                                              0.125                                                                              6.0 68%   88%   89%                                        16   AlB.sub.12 (1)                                                                     0.375                                                                             0.125                                                                              5.0 95%   >90%  94%                                        17   B.sub.12 C.sub.3 (1)                                                               0.375                                                                             0.125                                                                              6.0 47%   10%   74%                                        18   SiB.sub.4 (1)                                                                      0.75                                                                              0.125                                                                              5.0 76%   42%   83%                                        19   SiB.sub.6 (1)                                                                      0.375                                                                             0.125                                                                              6.0 66%   18%   92%                                        20   BN(1)                                                                              0.375                                                                             0.125                                                                              6.0 47%   10%   89%                                        21   CaB.sub.6 (1)                                                                      0.375                                                                             0.125                                                                              6.0 65%   23%   86%                                        22   W.sub.2 B.sub.5 (2)                                                                0.375                                                                             0.125                                                                              6.0 75%   81%   94%                                        23   VB.sub.2 (1)                                                                       0.375                                                                             0.125                                                                              3.0 99%   49%   93%                                        24   CrB(2)                                                                             1.25                                                                              0.25 4.0 80%   14%   55%                                        25   CrB.sub.2 (1)                                                                      0.375                                                                             0.125                                                                              5.0 82%   21%   73%                                        26   Cr.sub.5 B.sub.3 (1)                                                               0.375                                                                             0.125                                                                              6.0 86%   19%   69%                                        27   MoB(1)                                                                             1.50                                                                              0.50 1.75                                                                              95%   82%   87%                                        28   MoB.sub.2 (1)                                                                      0.75                                                                              0.25 2.0 98%   71%   94%                                        29   ZrB.sub.12 (2)                                                                     0.375                                                                             0.125                                                                              6.0 81%   53%   90%                                        30   UB.sub.2 (2)                                                                       0.375                                                                             0.125                                                                              6.0 95%   11%   67%                                        __________________________________________________________________________

EXAMPLE 31

In this example, propylene oxide was prepared in accordance with theinstant invention. A stirred one liter autoclave was charged with 2 g.of tungsten boride (WB), 50 g. tertiary butyl hydroperoxide, and 100 g.tertiary butanol. The autoclave was sealed and flushed with nitrogen.Then 84 g. of propylene were pressured into the sealed autoclave and thereaction mixture was heated with stirring at 118° to 122° C. for 4hours. The pressure maintained in the autoclave during the reactionsequence was substantially autogenous. Propylene oxide yield valuesusing GLC A% analysis were >65%.

EXAMPLE 32

In this example, the procedure in Example 31 was repeated with theexception that the solvent used was 100 g. benzene instead of thetertiary butanol. Propylene oxide yield values using GLC A% were >90%.

EXAMPLE 33

In this example, the procedure in Example 31 was repeated with theexception that the solvent was 100 g. propylene dichloride instead ofthe tertiary butanol. Propylene oxide yield values using GLC-A% were>90%.

EXAMPLE 34

In this example octene oxide was prepared by a method similar to that ofExample 1 with the exception that 25 g. of cumene hydroperoxide was usedas the epoxidizing agent instead of tertiary butyl hydroperoxide. Asignificant yield of octene oxide was observed.

EXAMPLE 35

In this example, N-octene oxide was prepared by the method of Example 34with the exception that aluminum dodecaboride (AlB₁₂) was utilized as acatalyst instead of tungsten boride. A significant yield of octene oxidewas observed.

EXAMPLES 36-39

In each of the following examples branched chain and cyclic olefiniccompounds were epoxidized in accordance with the invention, using theprocedures as set out in Example 1. The following epoxides were preparedfrom the corresponding olefin by reaction with tertiary butylhydroperoxide in the presence of a catalytic amount of tungsten boride(WB). The results are shown in Table II.

                                      TABLE II                                    __________________________________________________________________________               Catalyst                                                                           Hydroperoxide   Selectivity                                              Tungsten                                                                           Tertiary        epoxide                                                  Boride                                                                             Butyl   Conversion                                                                            (based on                                     Olefin (g) g    g       Hydroperoxide                                                                         hydroperoxide)                                __________________________________________________________________________    36 Vinylcyclohexene                                                           (42)       4    10      91%     93%.sup.(1)                                   37 Allyl Acetate                                                              (32)       4    10      10%     80%.sup.(2)                                   38 3-Cyclohexene                                                              Carbonitrile                                                                  (17)       4     8      52%     90%.sup.(2)                                   39 Dicyclopentadiene                                                          (60)       4    10      92%     39%.sup.(2)                                   __________________________________________________________________________     .sup.(1) Analysis based upon GLC area %                                       .sup.(2) Analysis based upon titrationwt %                               

EXAMPLE 40

In this example epichlorohydrin was produced in accordance with theinstant invention. A glass pressure bottle fitted with a stirrer wascharged with 100 g. allylchloride, 25 g. 90% t-butylhydroperoxide and 3g. tungsten boride (WB). The charged mass was heated to 108° C.-110° C.with stirring and held for 24 hours. The pressures maintained during thereaction sequence was autogenous. Recoverable amounts of epichlorohydrinwere observed.

EXAMPLE 41

In this example ethylene oxide was produced in accordance with theinstant invention. A stirred one liter autoclave was charged with 12 g.aluminum dodecaboride (AlB₁₂) 50 g. tertiary butyl hydroperoxide and 150g. tertiary butyl alcohol. The autoclave was sealed and flushed withethylene and pressurized. The autoclave was heated to 110° C. and apressure of 800 psig maintained for 4 hours. During this period, thetemperature range of the reaction mixture varied from about 109° C.-112°C. The effluent reaction product mixture showed recoverable amounts ofethylene oxide.

While the invention has been explained in relation to its preferredembodiment, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification and is intended to cover such modifications as fall withinthe scope of the appended claims.

What is claimed is:
 1. A method for the liquid phase epoxidation of anolefin having from about 2 to about 60 carbon atoms with an organichydroperoxide comprising the step of:intimately contacting said olefinwith said organic hydroperoxide at lower temperatures of about 25° C. toabout 200° C. and pressures sufficient to maintain the product andreactants substantially in liquid phase in the presence of acatalytically effective amount of a binary boride of boron and a metalselected from the group consisting of vanadium, niobium and tantalum. 2.The method of claim 1 wherein the said metal is niobium.
 3. The methodof claim 1 wherein said binary boride compound is NbB.
 4. The method ofclaim 1 wherein said metal is tantalum.
 5. The method of claim 1 whereinsaid binary boride is selected from a group consisting of TaB and TaB₂.6. The method of claim 1 wherein said metal is vanadium.
 7. The methodof claim 1 wherein said binary boride is VB₂.